Stock Based Compensation (Details 2) (USD $)	9 Months Ended
Sep. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Balance at January 1, 2011	757,414
Grants	381,840
Forfeitures	(65,592)
Vested and Issued	(339,138)
Balance at September 30, 2011	734,524
Weighted Average Grant Date Fair Value Per Share - Balance at January 1, 2011	$ 37.32
Weighted Average Grant Date Fair Value Per Share - Grants	$ 47.98
Weighted Average Grant Date Fair Value Per Share - Foreitures	$ 40.84
Weighted Average Grant Date Fair Value Per Share - Vested and issued	$ 38.25
Weighted Average Grant Date Fair Value Per Share - Balance at September 30, 2011	$ 42.22

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(c)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration